Communication device and method for receiving data

ABSTRACT

According to various examples, a communication device is described comprising a memory configured to store data received in one or more first transmissions of a transmission process according to a retransmission protocol, a receiver configured to receive a second transmission of data of the transmission process, a combiner configured to combine the data received in the second transmission with the data stored in the memory, a determiner configured to determine whether the second transmission was interfered by a communication resource deallocation and a controller configured to maintain data storage of the received data of the transmission process stored in the memory as received data of the transmission process if the second transmission was interfered by a communication resource deallocation.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority from European PatentApplication No. EP 19 163 673.7, filed on Mar. 19, 2019, the content ofit being hereby incorporated by reference in its entirety for allpurposes.

TECHNICAL FIELD

Exemplary implementations described herein generally relate tocommunication devices and methods for receiving data.

BACKGROUND

In a 5G (Fifth Generation) mobile communication system communicationresources allocated for data transmission to a mobile terminal may bepre-empted to provide another mobile terminal with a high prioritycommunication service. This allows ensuring quality requirements of thehigh priority communication service but may lead to performancedegradation for the mobile terminal whose communication resources arepre-empted. Accordingly, approaches to reduce performance degradationcaused by pre-emption of communication resources are desirable.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, the same reference characters generally refer to thesame parts throughout the different views. The drawings are notnecessarily to scale, emphasis instead generally being placed uponillustrating the principles of the invention. In the followingdescription, various aspects are described with reference to thefollowing drawings, in which:

FIG. 1 shows a communication system, e.g. a 5G (Fifth Generation)communication system.

FIG. 2 illustrates pre-emption with a posteriori signaling.

FIG. 3 shows a HARQ (Hybrid Automatic Repeat Request) unit.

FIG. 4 shows a flow diagram illustrating a typical HARQ processing.

FIG. 5 shows a flow diagram illustrating a HARQ processing with HARQbuffer flushing in case of pre-emption.

FIG. 6 shows a flow diagram illustrating a HARQ processing according toan example with two HARQ buffers for a HARQ process.

FIG. 7 illustrates the processing according to FIG. 6 when pre-emptiondoes not take place.

FIG. 8 illustrates the processing according to FIG. 6 when pre-emptiondoes take place.

FIG. 9 shows a communication device according to various examples.

FIG. 10 shows a flow diagram illustrating a method for receiving data,for example performed by a communication device, according to variousexamples.

DESCRIPTION OF EXEMPLARY IMPLEMENTATIONS

The following detailed description refers to the accompanying drawingsthat show, by way of illustration, specific details and aspects of thisdisclosure in which the invention may be practiced. Other aspects may beutilized and structural, logical, and electrical changes may be madewithout departing from the scope of the invention. The various aspectsof this disclosure are not necessarily mutually exclusive, as someaspects of this disclosure can be combined with one or more otheraspects of this disclosure to form new aspects.

FIG. 1 shows a communication system 100, e.g. a 5G (Fifth Generation)communication system as specified by 3GPP (Third Generation PartnershipProject).

The communication system 100 includes a radio access network (RAN, e.g.according to 5G NR (New Radio)) 101 and a core network (e.g. a 5G core)102. The radio access network 101 may include base (transceiver)stations (e.g. gNodeBs according to 5G) 103. Each base station 103provides radio coverage for one or more mobile radio cells 104 of theradio access network 101.

A mobile terminal (also referred to as UE, user equipment, or MS, mobilestation) 105 located in one of the mobile radio cells 104 (in thisexample the middle radio cell 104) may communicate with the core network102 and with other mobile terminals 105 via the base station providingcoverage in (in other words operating) the mobile radio cell.

Control and user data are transmitted between a base station 103 and amobile terminal 105 located in the mobile radio cell 104 operated by thebase station 103 over the air interface 106 on the basis of a multipleaccess method.

The base stations 103 are connected to the core network, e.g. to an UPF(user plane function) 107 (e.g. via an NG3 interface) and an Access andMobility Management Function (AMF) 108 (e.g. via an NG2 interface). Thecore network 102 includes further components such as a SessionManagement Function (SMF) 109, a Unified Data Management (UDM) 110 and aNetwork Repository Function (NRF) 111. The components of the corenetwork 102 may be directly connected via various interfaces or may beconnected via one or more of the other components.

To communicate via the air interface 106, the mobile terminal includescomponents like an antenna 112, a radio frontend 113, a basebandprocessor 114 and a HARQ (Hybrid Automatic Repeat Request) processor (orHARQ unit) 115.

For 5th Generation New Radio (5G NR) mobile communications, theInternational Telecommunication Union (ITU) has defined three servicecategories: Enhanced Mobile Broadband (eMBB), Ultra Reliable Low LatencyCommunications (URLLC), and Massive Machine-Type Communications (mMTC).

Ultra-Reliable and Low-Latency Communication (URLLC) is about serviceswith low-latency and high reliability. These are services that arerequired to have the shortest response times and virtually no failure.Examples are automatic driver assistants, which automatically controlmotor vehicles, or the remote maintenance of plants.

In a communication system providing URLLC services, higher priorityservices may pre-empt other lower priority on-going services. Forexample, in an NR 101, a gNodeB 103 may pre-empt PDSCH (PhysicalDownlink Shared Channel) resources already assigned to a lower-priorityservice in order to serve a URLLC service. Pre-emption means that thecommunication resources (e.g. PDSCH resources in the present example)which are already assigned for a certain data transmission (to a datatransmission of the lower priority service in this example) arede-allocated for re-allocation to another data transmission (to a datatransmission of the URLLC service in this example). The pre-emptioncauses a performance degradation to the lower priority service(contemplated to use the pre-empted PDSCH resources). In some NRscenarios, pre-emption (whether pre-emption occurred or not) is signaleda posteriori.

FIG. 2 illustrates pre-emption with a posteriori signaling.

In FIG. 2, time flows from left to right and the radio resource (i.e.communication resource) allocation is indicated by boxes 201 to 205. Aradio resource box 201 to 205 may for example correspond to anallocation of a certain frequency range (i.e. carriers) indicated by itsheight in vertical direction for a certain time indicated by its lengthin horizontal (i.e. time) direction.

First communication resources 201 are allocated to a first UE denoted“UE0”, second communication resources 202 are allocated to a second UEdenoted “UE1” and third communication resources 203 are allocated to athird UE denoted “UE2”. The communication resources 201 to 203 arelocated in a first pre-emption period 206 and no pre-emption takes placeso there is no pre-emption signaled at the end of the first pre-emptionperiod 206.

In a second pre-emption period 207, however, a part of fourthcommunication resources 204 which originally had been allocated to UE0are re-allocated to a fourth UE denoted UE3. This means that UE3 isallocated fifth communication resources 205 which overlap with thefourth communication resources 204, for example because UE3 uses a URLLCservice which has priority over the service for which UE0 has beenallocated the fourth communication resources 204. Thus, for example, thedata which the UE0 receives (e.g. from a base station 203) in theoverlap between the fourth communication resources 204 and the fifthcommunication resources 205 (shown hatched in FIG. 2) are not actuallydata intended for the UE0. Instead, they are for example data sent bythe base station 103 to UE3. However, the UE0 only gets knowledge ofthis when a pre-emption indication 208 is sent at the end of the secondpre-emption period 207, e.g. by base station 103.

At that time, UE0 may already have combined the data received via thecommunication resources in the overlap with earlier data (e.g. datareceived via the first communication resources 201), e.g. when it uses aHARQ process. Namely, in case a current transmission via thecommunication resources in the overlap is a retransmission in a HARQprocess, UE0 may perform a combining operation with the originalcontents of a HARQ memory (i.e. the earlier data). Thus, the earlierdata may be corrupted or at least its quality (regarding its capabilityto be decoded correctly) may be reduced. This results in performancedegradation for UE0. The combination may for example be a combination ofdemodulated soft bits, typically log-likelihood ratios (LLRs), of theearlier data and the data received in via the overlapping communicationresources.

Ideally, to minimize performance degradation caused by pre-emption of alower priority service, the communication device receiving data for thelower priority service would zero those LLRs (Log-likelihood ratios)derived from received data affected by pre-emption.

However, zeroing LLRs has the drawback of complexity since it requires asecond combining operation which is not feasible in most real timesystems and exact mapping of preempted LLRs.

Alternatively, the communication device may flush those HARQ processesaffected by pre-emption.

Flushing a HARQ process has a performance drawback since the wholehistory of transmissions and possible retransmissions for the HARQprocess is lost. This may lead to failure of decoding when a maximumnumber of transmissions has been reached and may thus require higherlayer retransmissions.

In the following, approaches to minimize or at least reduce theperformance degradation caused by pre-emption are described.

According to various examples, two versions of HARQ process data arekept temporarily (a version with and a version without combining acurrent transmission) and once a pre-emption indication is signaled, thereceiving communication device (e.g. UE 105) chooses which version ofthe HARQ process data is the best one and discards the other version.

By this approach, with respect to zeroing LLRs, a complexity reductionmay be achieved and, in scenarios where full PDSCH code blocks arepre-empted, optimal performance can be achieved. With respect toflushing a HARQ process, a performance advantage can be achieved sincethe history of the HARQ process is not lost. This can be seen to come atthe price of slightly more complex HARQ memory management.

For example, suppose that SNR (signal-to-noise ratio) is so that a PDSCHrequires N retransmissions in average and suppose that a maximum of N+1retransmissions are allowed (e.g. N=3). Suppose further that the Nthretransmission of the PDSCH is pre-empted. With high probability, acommunication device using HARQ flushing will not be able to decode thedata transmitted via the PDSCH after N+1 retransmissions. However, withhigh probability, a communication operating according to the approachdescribed above (with two versions of HARQ process data) will be able todecode PDSCH after N+1 retransmissions.

In the following, typical HARQ processing, HARQ processing with HARQflushing and a HARQ processing according to the approach described abovewith two versions of HARQ process data are described in the followingwith reference to FIGS. 4, 5 and 6, respectively, based on a HARQ unitas illustrated in FIG. 3.

FIG. 3 shows a HARQ unit 300.

The HARQ unit 300 for example corresponds to the HARQ unit 115 of the UE105.

The HARQ unit 300 receives data received by the UE 105, for example fromthe baseband processor 114, via an input 301. The data is for example inthe form of MAC PDUs (Medium Access Control Packet Data Units). A switch302 distributes the received data to the corresponding HARQ processes303. For each HARQ process 303, there is in particular a HARQ buffer 304and corresponding control (e.g. controlling HARQ feedback etc.) 305. TheHARQ buffers are implemented by a memory 306 of the HARQ unit 300 andthe controls 305 are implemented by a controller 307 of the HARQ unit300.

The HARQ unit 300 further includes a decoder 308 and an output 309 viawhich it outputs data which has been successfully decoded (i.e. passederror detection).

FIG. 4 shows a flow diagram 400 illustrating a typical HARQ processing.

The flow starts in an idle state 401.

In 402, a new HARQ process 303 is established. For example, the UE 105including the HARQ unit 300 is to receive data from a base station 103.

In 403, a HARQ buffer 304 is allocated for the new HARQ process 303 inthe memory 306.

In 404, data transmission is performed, e.g. the UE 105 receives dataassociated with the HARQ process 303.

In 405, it is checked whether new data has been received (which will bethe case for the initial data transmission but may not be the case forlater transmissions which may be retransmissions). If no new data hasbeen received, i.e. the transmission of data has been a retransmission,the received data is combined with the content of the HARQ buffer 304 in406. If new data has been received, the combination is skipped.

In 407, the decoder 308 decodes the received data or, as the case maybe, the result of the combination.

In 408, it is checked by controller 307 whether the result of thedecoding passes an error detection check, e.g. a CRC (cyclic redundancycheck).

If the error detection check is passed, the decoded data is output viaoutput 309 and the HARQ buffer is freed in 409.

If the error detection check is not passed, the received data or, as thecase may be, the result of the combination is stored in the HARQ bufferin 410 and data transmission continues.

FIG. 5 shows a flow diagram 500 illustrating a HARQ processing with HARQbuffer flushing in case of pre-emption.

The flow starts in an idle state 501.

In 502, a new HARQ process 303 is established. For example, the UE 105including the HARQ unit 300 is to receive data from a base station 103.

In 503, a HARQ buffer 304 is allocated for the new HARQ process 303 inthe memory 306.

In 504, data transmission is performed, e.g. the UE 105 receives dataassociated with the HARQ process 303.

In 505, it is checked whether new data has been received (which will bethe case for the initial data transmission but may not be the case forlater transmissions which may be retransmissions). If no new data hasbeen received, i.e. the transmission of data has been a retransmission,the received data is combined with the content of the HARQ buffer 304 in506. If new data has been received, the combination is skipped.

In 507, the decoder 308 decodes the received data or, as the case maybe, the result of the combination.

In 508, it is checked by controller 307 whether the result of thedecoding passes an error detection check, e.g. a CRC (cyclic redundancycheck).

If the error detection check is passed, the decoded data is output viaoutput 309 and the HARQ buffer is freed in 509.

If the error detection check is not passed, the received data or, as thecase may be, the result of the combination is stored in the HARQ bufferin 510.

In 511, it is checked whether pre-emption has occurred, i.e. whether apre-emption indication has been received by the UE 105.

If no pre-emption has occurred, the UE 105 continues data transmission.

If pre-emption has occurred, the HARQ buffer 304 is flushed in 512 anddata transmission is continued.

FIG. 6 shows a flow diagram 600 illustrating a HARQ processing accordingto an example with two HARQ buffers 304 for a HARQ process 303.

The flow starts in an idle state 601.

In 602, a new HARQ process 303 is established. For example, the UE 105including the HARQ unit 300 is to receive data from a base station 103.

In 603, a HARQ buffer 304 is allocated for the new HARQ process 303 inthe memory 306.

In 604, data transmission is performed, e.g. the UE 105 receives dataassociated with the HARQ process 303.

In 605, it is checked whether new data has been received (which will bethe case for the initial data transmission but may not be the case forlater transmissions which may be retransmissions). If no new data hasbeen received, i.e. the transmission of data has been a retransmission,the received data is combined with the content of the HARQ buffer 304 in606. This may for example be a combination of soft values (e.g. LLRs).If new data has been received, the combination is skipped.

In 607, the decoder 308 decodes the received data or, as the case maybe, the result of the combination.

In 608, it is checked by controller 307 whether the result of thedecoding passes an error detection check, e.g. a CRC (cyclic redundancycheck).

If the error detection check is passed, the decoded data is output viaoutput 309 and the HARQ buffer is freed in 609.

If the error detection check is not passed, a temporary (second) HARQbuffer is allocated in the memory 306 for the HARQ process 303 and in611 the received data or, as the case may be, the result of thecombination is stored in the temporary HARQ buffer.

In 612, it is checked whether pre-emption has occurred, i.e. whether apre-emption indication has been received by the UE 105.

If no pre-emption has occurred, the content of the HARQ buffer is set tothe content of the temporary HARQ buffer (e.g. be setting the temporaryHARQ buffer to be the HARQ buffer of the HARQ process) in 613.

If pre-emption has occurred, this is skipped, i.e. the content of theHARQ buffer is kept the same. This means that the information of thenewly received data is discarded.

In 614, the temporary HARQ buffer is freed (i.e. the correspondingmemory area in the memory 306 is de-allocated) and data transmission iscontinued.

In summary, upon a PDSCH retransmission, the UE reads the HARQ bufferassigned to the current HARQ process from HARQ memory, combines it withthe current transmission and, in case decoding is not successful, the UEstores the results back to HARQ memory. In the approaches as illustratedin FIGS. 4 and 5, the same HARQ buffer is used to store back the resultsafter combining.

In contrast, according to the approach illustrated in FIG. 6, thecombining results are not stored back to the same HARQ buffer in HARQmemory but a new location is allocated for them. This means thattemporarily two HARQ buffers are stored in memory for the same HARQprocess. Two HARQ buffers are temporarily allocated to the HARQ processuntil the pre-emption indication arrives. Upon reception of thepre-emption indication, the best HARQ buffer for the HARQ process can bechosen and the other HARQ buffer is freed up.

FIG. 7 illustrates the processing according to FIG. 6 when pre-emptiondoes not take place.

In a first stage 701, an initial transmission 704 is received by the UEand the received data is stored in a HARQ buffer 705 in HARQ memory 706.

In a second stage 702, the UE receives a retransmission 707. The datareceived in the retransmission is combined (according to 606) with thedata of the initial transmission stored in HARQ buffer 705 to combineddata 708. It is assumed in this example that the combined data 708cannot be decoded to data that passes the CRC. Accordingly, the combineddata 708 is stored according to 611 in a temporary HARQ buffer 709allocated in HARQ memory 706.

In this example, no pre-emption indication is received (e.g. at the endof the pre-emption period during which the retransmission 707 tookplace, see FIG. 2). Therefore, in a third stage 703, the temporary HARQbuffer 709 is set to be the HARQ buffer from now on and the (old) HARQbuffer 705 is de-allocated. In other words, the combined data is kept asthe data of the HARQ process. This can be seen as keeping the best HARQbuffer for the HARQ process.

FIG. 8 illustrates the processing according to FIG. 6 when pre-emptiondoes take place.

In a first stage 801, an initial transmission 804 is received by the UEand the received data is stored in a HARQ buffer 805 in HARQ memory 806.

In a second stage 802, the UE receives a retransmission 807. The datareceived in the retransmission is combined (according to 606) with thedata of the initial transmission stored in HARQ buffer 805 to combineddata 808. It is assumed in this example that the combined data 808cannot be decoded to data that passes the CRC. Accordingly, the combineddata 808 is stored according to 611 in a temporary HARQ buffer 809allocated in HARQ memory 806.

In this example, a pre-emption indication is received (e.g. at the endof the pre-emption period during which the retransmission 807 tookplace, see FIG. 2). Therefore, in a third stage 803, the temporary HARQbuffer 809 is de-allocated and the HARQ buffer 805 continues to be theHARQ buffer. In other words, the data without the data received from theretransmission 804 is kept as the data of the HARQ process. This can beseen as keeping the best HARQ buffer for the HARQ process.

This process is then continued analogously for further retransmissions,i.e. the second stage 702, 802 and the third stage 803, 804 are repeatedfor further retransmissions until decoding has been successful and newdata is transmitted.

It should be noted that the combination may mean a combination of softbits (e.g. LLRs) for data for which both the initial transmission 704,804 as well as the retransmission 707, 708 contain data. However, thecase may occur that the data transmitted in the initial transmission704, 804 and the data transmitted in the retransmission 707, 708 onlypartially overlap. Then, only the overlapping parts are combined.

It should further be noted that in a UE the HARQ memory is typicallydimensioned for the worst case (e.g. maximum number of carriers or worstchannel conditions). Therefore, in a common scenario, the HARQ memory706, 806 is typically not fully utilized. This allows to temporarilykeep double buffering for some HARQ processes. As explained above, oncea pre-emption indication has been received, only the best HARQ buffer iskept for each of the received HARQ processes since the last pre-emptionindication.

In summary, according to various examples, a communication device isprovided as illustrated in FIG. 9.

FIG. 9 shows a communication device 900.

The communication device 900 includes a memory 901 configured to storedata received in one or more first transmissions of a transmissionprocess according to a retransmission protocol and a receiver 902configured to receive a second transmission of data of the transmissionprocess.

Further, the communication device 900 includes a combiner 903 configuredto combine the data received in the second transmission with the datastored in the memory and a determiner 904 configured to determinewhether the second transmission was interfered by a communicationresource deallocation.

The communication device 900 further includes a controller 905configured to maintain data storage of the received data of thetransmission process stored in the memory (i.e. keeps the received dataof the transmission process stored in the memory) as received data ofthe transmission process if the second transmission was interfered by acommunication resource deallocation.

According to various examples, in other words, a communication devicewaits until it knows whether data received in a second retransmission(i.e. newly received data) have been influenced by pre-emption ofcommunication resources and only when it has this knowledge decideswhether to keep the information of the newly received data (if thesecond transmission was not influenced) or to discard it and revert toearlier data (if the second transmission was influenced). Until thatdecision, the communication device keeps data received earlier (withoutcombination with the newly received data) such that it can revert to theearlier data and as well keeps the information of the newly receiveddata, e.g. in form of a combination of the data received earlier withthe newly received data.

If the data received in the second transmission together with theearlier data (received in the one or more first transmissions) aresufficient for decoding, the communication device may immediatelyperform decoding, i.e. there is no need for it to wait for informationon whether the second transmission was interfered (i.e. disturbed,altered or influenced) by pre-emption. However, it is likely that inthat case, the second transmission was not influenced by pre-emptionbecause it allowed for successful decoding. In other words, according tovarious examples, the processing of the determiner and the controller isonly carried out if the result of the combining by the combiner is notsufficient for successful decoding (e.g. such that the result of thedecoding passes an error check such as a CRC check).

The communication device may be capable of combining additionaltransmissions (e.g. a third, fourth transmission and so on) with some orall available versions of the transmission process stored in memory, maybe capable of storing the additional combined and non-combined resultsin memory, and may be capable of discarding several versions of thereceived data of the transmission process. This means that for each ofone or more second transmissions of data of the transmission process, aresult of combination with data stored in the memory may be stored, evenbefore it has been decided whether the received data resulting from thecombination of data received in an earlier second transmission is to bediscarded. It may later be decided which version, i.e. the result ofwhich combination is to be kept as received data of the transmissionprocess.

The determiner may be configured to determine whether the secondtransmission was interfered by a communication resource deallocationbased on whether the communication device has detected a resourcedeallocation, for example by analyzing channel properties, LLRproperties, interference estimations, etc.

According to various examples method as illustrated in FIG. 10 isperformed.

FIG. 10 shows a flow diagram 1000 illustrating a method for receivingdata, for example performed by a communication device.

In 1001, the communication device receives (first) data in one or morefirst transmissions of a transmission process according to aretransmission protocol.

In 1002, the communication device stores the data received in the one ormore first transmissions in a memory.

In 1003, the communication device receives (second) data in a secondtransmission of the transmission process.

In 1004, the communication device combines the data received in thesecond transmission with the data received in the one or more firsttransmissions.

In 1005, the communication device determines whether the secondtransmission was interfered by a communication resource deallocation.

In 1006, the communication device maintains data storage of the datareceived in the one or more first transmissions as received data of thetransmission process if the second transmission was interfered by acommunication resource deallocation. For example, in 1006, thecommunication device maintains data storage of the data received in theone or more first transmissions as received data of the transmissionprocess in response to the second transmission being interfered by acommunication resource deallocation.

The components of the communication device (such as in particular thecombiner and the determiner) may for example be implemented by one ormore processors. A “processor” may be understood as any kind of a logicimplementing entity, which may be special purpose circuitry or aprocessor executing software stored in a memory, firmware, or anycombination thereof. Thus a “processor” may be a hard-wired logicprocessor or a programmable logic processor such as a programmableprocessor, e.g. a microprocessor. A “processor” may also be a processorexecuting software, e.g. any kind of computer program. Any other kind ofimplementation of the respective functions which will be described inmore detail below may also be understood as a “processor”. Thecommunication device may for example be at least partially implementedby a transceiver which may for example be at least partially implementedby a modem (e.g. an LTE modem), a baseband processor or othertransceiver components or also by an application processor. Thecommunication device may for example be a communication terminal as suchand may include typical communication terminal devices such as atransceiver (including e.g. a baseband processor, one or more filters,transmit chains, receive chains, amplifiers etc.), an antenna, asubscriber identity module, an application processor, a memory etc.

The following examples pertain to further exemplary implementations.

Example 1 is a communication device as illustrated in FIG. 9.

In Example 2 the subject-matter of Example 1 may optionally include thecontroller being configured to store the result of the combining asreceived data of the transmission process in the memory if the secondtransmission was not interfered by a communication resourcedeallocation.

In Example 3 the subject-matter of Example 1 or 2 may optionally includethe controller being configured to discard the result of the combiningif the second transmission was interfered by a communication resourcedeallocation.

In Example 4 the subject-matter of any one of Examples 1 to 3 mayoptionally include the controller being configured to discard thereceived data of the transmission process stored in the memory if thesecond transmission was not interfered by a communication resourcedeallocation.

In Example 5 the subject-matter of any one of Examples 1 to 4 mayoptionally include the receiver being configured to receive one or moresecond transmissions of data of the transmission process and thecombiner, the determiner and the controller being configured to, foreach of the one or more second transmissions of data, combine the datareceived in the second transmission with the data stored in the memory;determine whether the second transmission was interfered by acommunication resource deallocation; and maintain data storage of thereceived data of the transmission process stored in the memory asreceived data of the transmission process if the second transmission wasinterfered by a communication resource deallocation.

In Example 6 the subject-matter of any one of Examples 1 to 5 mayoptionally include the determiner being configured to determine whetherthe second transmission was interfered by a communication resourcedeallocation based on whether the communication device has received acommunication resource deallocation message.

In Example 7 the subject-matter of any one of Examples 1 to 6 mayoptionally include the determiner being configured to determine whetherthe second transmission was interfered by a communication resourcedeallocation based on whether the communication device has detected aresource deallocation.

In Example 8 the subject-matter of Example 6 or 7 may optionally includethe communication resource deallocation being a communication resourcepre-emption and the communication resource deallocation message being apre-emption indication.

In Example 9 the subject-matter of any one of Examples 1 to 8 mayoptionally include the second transmission being a retransmissionaccording to the retransmission protocol.

In Example 10 the subject-matter of any one of Examples 1 to 9 mayoptionally include the retransmission protocol being a Hybrid AutomaticRepeat Request protocol and the transmission process being a HybridAutomatic Repeat Request process.

In Example 11 the subject-matter of any one of Examples 1 to 10 mayoptionally include the controller being configured to check whether theresult of the combining is sufficient for decoding and free the memoryfrom the received data of the transmission process if the result of thecombining is sufficient for decoding.

In Example 12 the subject-matter of any one of Examples 1 to 11 mayoptionally include the controller being configured to check whether theresult of the combining is sufficient for decoding by decoding theresult of the combining and checking whether result of the decodingfulfills an error detection criterion.

In Example 13 the subject-matter of any one of Examples 1 to 12 mayoptionally include the combiner being configured to store the result ofthe combining in a further memory and the controller being configured tofree the further memory if the second transmission was interfered by acommunication resource deallocation.

In Example 14 the subject-matter of Example 13 may optionally includethe memory being a transmission process buffer and the further memorybeing a temporary transmission process buffer.

In Example 15 the subject-matter of Example 12 may optionally includethe controller being configured to set the temporary transmissionprocess buffer as the transmission process buffer if the secondtransmission was not interfered by a communication resourcedeallocation.

In Example 16 the subject-matter of any one of Examples 1 to 15 mayoptionally include the communication device being a mobile terminal of amobile communication system and the one or more first transmissions andthe second transmissions being transmissions via a downlink channel ofthe mobile communication system.

In Example 17 the subject-matter of any one of Examples 1 to 16 mayoptionally include the downlink channel being a Physical Downlink SharedChannel.

Example 18 is a method for receiving data as illustrated in FIG. 10.

In Example 19 the subject-matter of Example 18 may optionally includestoring the result of the combining as received data of the transmissionprocess in the memory if the second transmission was not interfered by acommunication resource deallocation.

In Example 20 the subject-matter of Example 18 or 19 may optionallyinclude discarding the result of the combining if the secondtransmission was interfered by a communication resource deallocation.

In Example 21 the subject-matter of any one of Examples 18 to 20 mayoptionally include discarding the received data of the transmissionprocess stored in the memory if the second transmission was notinterfered by a communication resource deallocation.

In Example 22 the subject-matter of any one of Examples 18 to 21 mayoptionally include receiving one or more second transmissions of data ofthe transmission process and, for each of the one or more secondtransmissions of data, combining the data received in the secondtransmission with the data stored in the memory; determining whether thesecond transmission was interfered by a communication resourcedeallocation; and maintaining data storage of the received data of thetransmission process in the memory as received data of the transmissionprocess if the second transmission was interfered by a communicationresource deallocation.

In Example 23 the subject-matter of any one of Examples 18 to 22 mayoptionally include determining whether the second transmission wasinterfered by a communication resource deallocation based on whether acommunication resource deallocation message has been received.

In Example 24 the subject-matter of any one of Examples 18 to 23 mayoptionally include determining whether the second transmission wasinterfered by a communication resource deallocation based on whether aresource deallocation has been detected.

In Example 25 the subject-matter of Example 23 or 24 may optionallyinclude the communication resource deallocation being a communicationresource pre-emption and the communication resource deallocation messagebeing a pre-emption indication.

In Example 26 the subject-matter of any one of Examples 18 to 25 mayoptionally include the second transmission being a retransmissionaccording to the retransmission protocol.

In Example 27 the subject-matter of any one of Examples 18 to 26 mayoptionally include the retransmission protocol being a Hybrid AutomaticRepeat Request protocol and the transmission process being a HybridAutomatic Repeat Request process.

In Example 28 the subject-matter of any one of Examples 18 to 27 mayoptionally include checking whether the result of the combining issufficient for decoding and freeing the memory from the received data ofthe transmission process if the result of the combining is sufficientfor decoding.

In Example 29 the subject-matter of any one of Examples 18 to 28 mayoptionally include checking whether the result of the combining issufficient for decoding by decoding the result of the combining andchecking whether result of the decoding fulfills an error detectioncriterion.

In Example 30 the subject-matter of any one of Examples 18 to 29 mayoptionally include storing the result of the combining in a furthermemory and freeing the further memory if the second transmission wasinterfered by a communication resource deallocation.

In Example 31 the subject-matter of Example 30 may optionally includethe memory being a transmission process buffer and the further memorybeing a temporary transmission process buffer.

In Example 32 the subject-matter of Example 29 may optionally includesetting the temporary transmission process buffer as the transmissionprocess buffer if the second transmission was not interfered by acommunication resource deallocation.

In Example 33 the subject-matter of any one of Examples 18 to 32 may beperformed by a mobile terminal of a mobile communication system and mayoptionally include the one or more first transmissions and the secondtransmissions being transmissions via a downlink channel of the mobilecommunication system.

In Example 34 the subject-matter of any one of Examples 18 to 33 mayoptionally include the downlink channel being a Physical Downlink SharedChannel.

According to a further example, a communication device receives aretransmission of data in a transmission process according to aretransmission protocol, combines data received in retransmission withdata of the transmission process before the retransmission while keepingthe data of the transmission process before the retransmission stored,determines whether the data retransmission was influenced by resourcedeallocation and if the data retransmission was influenced by resourcedeallocation uses the data of the transmission process before theretransmission as data of the transmission process and else uses thecombination as data of the transmission process.

It should be noted that one or more of the features of any of theexamples above may be combined with any one of the other examples.

While specific aspects have been described, it should be understood bythose skilled in the art that various changes in form and detail may bemade therein without departing from the spirit and scope of the aspectsof this disclosure as defined by the appended claims. The scope is thusindicated by the appended claims and all changes which come within themeaning and range of equivalency of the claims are therefore intended tobe embraced.

The invention claimed is:
 1. A communication device comprising: a memoryconfigured to store data received in one or more first transmissions ofa transmission process according to a retransmission protocol; areceiver configured to receive a second transmission of data of thetransmission process; a combiner configured to combine the data receivedin the second transmission with the data stored in the memory; adeterminer configured to determine whether the second transmission wasinterfered by a communication resource deallocation; and a controllerconfigured to maintain data storage of the received data of thetransmission process stored in the memory as received data of thetransmission process if the second transmission was interfered by acommunication resource deallocation, wherein the controller isconfigured to discard the received data of the transmission processstored in the memory if the second transmission was not interfered by acommunication resource deallocation, and wherein the determiner isconfigured to determine whether the second transmission was interferedby a communication resource deallocation based on whether thecommunication device has detected a resource deallocation by analyzingchannel properties, log-likelihood ratios (LLR) properties, and/orinterference estimations.
 2. The communication device of claim 1,wherein the controller is configured to store the result of thecombining as received data of the transmission process in the memory ifthe second transmission was not interfered by a communication resourcedeallocation.
 3. The communication device of claim 1, wherein thecontroller is configured to discard the result of the combining if thesecond transmission was interfered by a communication resourcedeallocation.
 4. The communication device of claim 1, wherein thereceiver is configured to receive one or more second transmissions ofdata of the transmission process and the combiner, the determiner andthe controller are configured to, for each of the one or more secondtransmissions of data, combine the data received in the secondtransmission with the data stored in the memory; determine whether thesecond transmission was interfered by a communication resourcedeallocation; and maintain data storage of the received data of thetransmission process stored in the memory as received data of thetransmission process if the second transmission was interfered by acommunication resource deallocation.
 5. The communication device ofclaim 1, wherein the determiner is configured to determine whether thesecond transmission was interfered by a communication resourcedeallocation based on whether the communication device has received acommunication resource deallocation message.
 6. The communication deviceof claim 5, wherein the communication resource deallocation is acommunication resource pre-emption and the communication resourcedeallocation message is a pre-emption indication.
 7. The communicationdevice of claim 1, wherein the second transmission is a retransmissionaccording to the retransmission protocol.
 8. The communication device ofclaim 1, wherein the retransmission protocol is a Hybrid AutomaticRepeat Request protocol and the transmission process is a HybridAutomatic Repeat Request process.
 9. The communication device of claim1, wherein the controller is configured to check whether the result ofthe combining is sufficient for decoding and free the memory from thereceived data of the transmission process if the result of the combiningis sufficient for decoding.
 10. The communication device of claim 1,wherein the controller is configured to check whether the result of thecombining is sufficient for decoding by decoding the result of thecombining and checking whether result of the decoding fulfills an errordetection criterion.
 11. The communication device of claim 10, whereinthe controller is configured to set a temporary transmission processbuffer as the transmission process buffer if the second transmission wasnot interfered by a communication resource deallocation.
 12. Thecommunication device of claim 1, wherein the combiner is configured tostore the result of the combining in a further memory and the controlleris configured to free the further memory if the second transmission wasinterfered by a communication resource deallocation.
 13. Thecommunication device of claim 12, wherein the memory is a transmissionprocess buffer and the further memory is a temporary transmissionprocess buffer.
 14. The communication device of claim 1, wherein thecommunication device is a mobile terminal of a mobile communicationsystem and wherein the one or more first transmissions and the secondtransmissions are transmissions via a downlink channel of the mobilecommunication system.
 15. The communication device of claim 14, whereinthe downlink channel is a Physical Downlink Shared Channel.
 16. A methodfor receiving data comprising: receiving data in one or more firsttransmissions of a transmission process according to a retransmissionprotocol; storing the data received in the one or more firsttransmissions in a memory; Receiving data in a second transmission ofthe transmission process; combining the data received in the secondtransmission with the data received in the one or more firsttransmissions; determining whether the second transmission wasinterfered by a communication resource deallocation; maintaining datastorage of the data received in the one or more first transmissions asreceived data of the transmission process if the second transmission wasinterfered by a communication resource deallocation; discarding thereceived data of the transmission process stored in the memory inresponse to determining the second transmission was not interfered by acommunication resource deallocation; and determining whether the secondtransmission was interfered by a communication resource deallocationbased on whether the communication device has detected a resourcedeallocation by analyzing channel properties, log-likelihood ratios(LLR) properties, and/or interference estimations.
 17. The method ofclaim 16, comprising storing the result of the combining as receiveddata of the transmission process in the memory if the secondtransmission was not interfered by a communication resourcedeallocation.
 18. The method of claim 16, comprising discarding theresult of the combining if the second transmission was interfered by acommunication resource deallocation.
 19. A communication devicecomprising: a memory configured to store data received in one or morefirst transmissions of a transmission process according to aretransmission protocol; a receiver configured to receive a secondtransmission of data of the transmission process; a combiner configuredto combine the data received in the second transmission with the datastored in the memory; a determiner configured to determine whether thesecond transmission was interfered by a communication resourcedeallocation; and a controller configured to maintain data storage ofthe received data of the transmission process stored in the memory asreceived data of the transmission process if the second transmission wasinterfered by a communication resource deallocation, and wherein thedeterminer is configured to determine whether the second transmissionwas interfered by a communication resource deallocation based on whetherthe communication device has detected a resource deallocation byanalyzing channel properties, log-likelihood ratios (LLR) properties,and/or interference estimations.